Tech Torque FRASER STRONACH

It’s no se­cret that ve­hi­cle man­u­fac­tur­ers are find­ing it dif­fi­cult to meet the in­creas­ingly tough ex­haust emission reg­u­la­tions im­posed by gov­ern­ments around the world.

This was high­lighted re­cently by the Volk­swa­gen diesel scan­dal, where the Ger­man man­u­fac­turer was found to have in­stalled so-called ‘de­feat soft­ware’ in its en­gine con­trol elec­tron­ics. This de­feat soft­ware recog­nised when the ve­hi­cle was on an emis­sions test-bed and al­tered the en­gine’s run­ning con­di­tions to clean up the ex­haust emission, es­pe­cially the pro­duc­tion of the var­i­ous ox­ides of ni­tro­gen col­lec­tively known as NOX.

With high com­bus­tion pres­sures and tem­per­a­tures, diesel en­gines pro­duce far more NOX than equiv­a­lent petrol en­gines. This re­sults in a ma­jor en­vi­ron­men­tal hur­dle. On the other side of the ledger, diesels pro­duce less car­bon diox­ide (or so-called green­house gas) than equiv­a­lent petrol en­gines. This is a ma­jor rea­son why so much de­vel­op­ment has been put into diesel en­gines over the last 15 years.

Fol­low­ing the Volk­swa­gen ex­posé, a re­port by the In­ter­na­tional Coun­cil on Clean Trans­porta­tion (ICCT) claimed that 93 per cent of both EU and US ve­hi­cles tested from six dif­fer­ent man­u­fac­tur­ers failed to meet cur­rent Euro 6 emission stan­dards un­der re­al­world test­ing. And, on av­er­age, the ve­hi­cles pro­duced seven times the amount of cer­ti­fied NOX emis­sions.

How­ever, this is just the tip of the ice­berg, as Euro 6 NOX reg­u­la­tions are due to be tight­ened fur­ther in 2017 and again in 2020. This is mir­rored in the USA where the En­vi­ron­men­tal Pro­tec­tion Agency (EPA) plans to in­tro­duce tougher Tier 3 emis­sions stan­dards in 2017, which will bring the na­tional EPA man­date into line with the even stricter Cal­i­for­nia Air Re­sources Board (CARB) stan­dards.

Car man­u­fac­tur­ers are say­ing all this is too much and that un­less the reg­u­la­tors cut them some slack in the form of so-called con­form­ity fac­tors, or change the test pro­ce­dures so they bet­ter re­flect real-world con­di­tions, then they sim­ply can’t meet the up­com­ing stan­dards. In­deed, some car­mak­ers are now say­ing diesels are no longer part of their for­ward plan­ning.

If all that sounds like bad news, then a re­cent an­nounce­ment by Daim­ler AG (the com­pany that makes Mercedesbenz) that it’s spend­ing Au$3.8bil­lion on its next-gen­er­a­tion diesel en­gine with the aim of meet­ing up­com­ing emis­sions stan­dards has to be good news.

This doesn’t just af­fect Mercedes-benz, as Daim­ler AG is now in a part­ner­ship with the Re­nault-nis­san Al­liance. So th­ese news diesel en­gines could also power Re­naults and Nis­sans some­time in the fu­ture. And who’s to say that Daim­ler AG won’t sell the en­gine to other car­mak­ers? What’s more, if Daim­ler AG can rise to the chal­lenge of meet­ing th­ese tough new reg­u­la­tions, it may spur other man­u­fac­tur­ers on to do the same.

Daim­ler AG has said its new al­la­lu­minium diesel will be a mo­du­lar de­sign and will be en­gi­neered for both north-south and east-west in­stal­la­tion, as well as for hy­brid ap­pli­ca­tions, all of which in­di­cates use in a di­verse range of mod­els.

The ba­sic en­gine will be a 2.0-litre, four-cylin­der that’s good for 143kw and 400Nm pro­duced from 1600-2400rpm. The en­gine will ini­tially ap­pear by late 2016 in Benz’s mid-sized E-class sedan.

As part of the mo­du­lar de­sign the en­gine can be cut down to a 1.5-litre, three-cylin­der for smaller pas­sen­ger cars, or it can be bumped up to a 3.0litre, six-cylin­der for big­ger and heav­ier ve­hi­cles. A three-litre could be achieved by dou­bling the 1.5-litre, three-cylin­der to make a V6, or adding two ex­tra cylin­ders to the four to make an in­line six. The ben­e­fit of a mo­du­lar de­sign is that com­po­nents in­clud­ing pis­tons, con­rods, valves, in­jec­tors and the like can be shared across all en­gine types, while cylin­der heads and camshafts can be shared be­tween a 1.5-litre triple and a 3.0-litre V6.

Daim­ler has said this en­gine will fea­ture Nanoslide cylin­der bore tech­nol­ogy, the same tech used in its all­con­quer­ing For­mula One car. It will also be un­der­square and run a low 15.5:1 com­pres­sion ra­tio, as well as two-stage ex­haust re­cir­cu­la­tion, fourth-gen­er­a­tion com­mon-rail in­jec­tion and SCR tech­nol­ogy.